Method of operating an internal combustion engine having a turbocharger

Abstract

A method and system for operating an internal combustion engine equipped with a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger is disclosed. A value of a parameter indicative of a temperature of an exhaust gas is determined, and an internal recirculation strategy of the exhaust gas is actuated if the determined value is lower than a predetermined threshold value thereof. The internal recirculation strategy includes interrupting a flowing of exhaust gas through the exhaust gas recirculation pipe, and opening an exhaust valve during an intake stroke of a piston of the internal combustion engine.

What is claimed is: 
     
       1. A method of operating an internal combustion engine having a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger, the method comprising:
 determining a value of a parameter indicative of a temperature of an exhaust gas; 
 measuring a temperature value of a coolant of the internal combustion engine, wherein the parameter is the temperature value of the coolant; and 
 actuating an internal recirculation strategy of the exhaust gas, if the determined value is lower than a predetermined threshold value thereof, wherein the internal recirculation strategy comprises: 
 interrupting a flowing of exhaust gas through the exhaust gas recirculation pipe; and 
 opening an exhaust valve during an intake stroke of a piston of the internal combustion engine. 
 
     
     
       2. The method according to  claim 1 , further comprising:
 determining a fuel requested quantity; and 
 actuating the internal recirculation strategy, if the determined value of the parameter is equal to or higher than the predetermined threshold value thereof and the determined fuel requested quantity is lower than a predetermined threshold value thereof. 
 
     
     
       3. A non-transitory computer readable medium comprising program code, which when executed on a computer, performs the method according to  claim 1 . 
     
     
       4. An electronic control unit for an internal combustion engine having a reciprocating piston defining a combustion chamber and exhaust gas valve allowing exhaust gas to exit the combustion chamber during an exhaust stroke of the piston, a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger, wherein the electronic control unit is configured to:
 determine a value of a parameter indicative of a temperature of an exhaust gas; and 
 actuate an internal recirculation strategy of the exhaust gas, if the determined value is lower than a predetermined threshold value thereof, wherein the internal recirculation strategy includes interrupting a flowing of exhaust gas through the exhaust gas recirculation pipe, and opening the exhaust valve during an intake stroke of the piston, 
 wherein the internal combustion engine includes an engine cooling system having a circulating coolant provided to cool the internal combustion engine, wherein the electronic control unit is further configured to: measure a temperature value of the coolant and use the temperature value as the parameter. 
 
     
     
       5. The electronic control unit according to  claim 3 , wherein the electronic control unit is further configured to:
 determine a fuel requested quantity to be injected into the combustion chamber; and 
 actuate the internal recirculation strategy, if the determined value of the parameter is equal to or higher than the predetermined threshold value thereof and the determined fuel requested quantity is lower than a predetermined threshold value thereof. 
 
     
     
       6. An internal combustion engine comprising:
 a reciprocating piston defining a combustion chamber having an exhaust gas valve allowing exhaust gas to exit the combustion chamber during an exhaust stroke of the piston; 
 a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger; 
 an electronic control unit ( 450 ) configured to:
 determine a value of a parameter indicative of a temperature of an exhaust gas; 
 actuate an internal recirculation strategy of the exhaust gas, if the determined value is lower than a predetermined threshold value thereof, wherein the internal recirculation strategy comprises interrupting a flowing of exhaust gas through the exhaust gas recirculation pipe, and opening the exhaust valve during an intake stroke of the piston; and 
 
 an engine cooling system having a circulating coolant provided to cool the internal combustion engine, wherein the parameter is a temperature value of the coolant. 
 
     
     
       7. The internal combustion engine according to  claim 6 , wherein the electronic control unit is further configured to:
 determine a fuel requested quantity to be injected into the combustion chamber; and 
 actuate the internal recirculation strategy, if the determined value of the parameter is equal to or higher than the predetermined threshold value thereof and the determined fuel requested quantity is lower than a predetermined threshold value thereof.